It is well known that the object of cleaning one's teeth is to remove the layer of plaque that is deposited on them and which is the prime cause of tooth decay and gum diseases.
It is almost impossible, without assistance, to see whether one has removed all the plaque by brushing. To assist in proper brushing of the teeth disclosing agents are known which are placed in the mouth and which dye the plaque a colour which stands out against the clean tooth enamel. Brushing can then be continued until all the dyed areas have been removed.
Conventional disclosing agents are available in many forms, such as tablets, liquids or incorporated into a dentifrice as described in my South African Pat. No. 78/2334.
Although these disclosing agents are acknowledged as being effective in disclosing plaque it has been found very difficult to persuade people to use them on a regular basis. One of the main reasons for this is that all the existing disclosing agents use a water soluble dye to stain the plaque. A reasonably high dye concentration is required in order to produce the necessary colour contrast between plaque and enamel, and it is found that this dye concentration causes staining of the skin, tongue and mucosa. Although the staining is not serious and disappears in time, it is clearly a factor which holds people back from using disclosing agents on a regular basis.